David Cameron
The Eton-educated prime minister is expected to make the announcement in a speech todayReuters

The UK prime minister is expected to declare a "war on mediocrity" as part of a plan to improve schools in England.

Eton-educated Cameron will announce that a Conservative government would tackle "coasting" schools and force almost 3,500 schools rated as "requiring improvement" into new leadership.

"As parents we're hardwired to want the best for our kids. No one wants their child to go to a failing school – and no one wants to them to go to a coasting school either," he will say.

"So this party is clear. Just enough is not good enough. That means no more sink schools - and no more 'bog standard' schools either. We're waging an all-out war on mediocrity, and our aim is this: the best start in life for every child, wherever they're from – no excuses."

The move could see the schools taken over by a "superhead", high-ranking locals schools or academy trusts.

Labour argued that Cameron's schools policy is "damaging" the education system and "failing" to close the learning gap between disadvantaged children and the rest.

"Many parents will be shocked to learn that Cameron's government has changed the rules to allow unqualified teachers into the classroom on a permanent basis, leading to a 16 per cent rise in the last year alone," said Tristram Hunt, Labour's shadow education secretary.

"The surest way to raise standards in every lesson, in every school, is to improve the quality of teaching in the classroom.

"That begins with an end to Cameron's unqualified teachers policy. Labour will ensure that all teachers are qualified and continue to train to improve their teaching as a condition to remaining in the classroom.

"This is how we improve the learning and life chances for all children and raise our international position in reading, writing and maths."

The prime minister's speech will come with less than 100 days before the general election in May.

The latest YouGov poll for The Sunday Times put Labour on a three-point lead over the Tories (35% vs 32%), with Ukip on 15%, the Liberal Democrats on 7% and the Greens on 6%.